The project NEURODYS has started as a major new European effort to clarify the biological bases of developmental dyslexia, or specific reading disability. Dyslexia is a common, severe learning disorder that affects at least 5% of school children and it has a strong biological basis. Confirming relations between dyslexia, candidate genes and brain regions requires large samples from diverse cultures and languages – a characteristic European feature.

NEURODYS links 15 top research groups and clinics from 9 different countries. It also covers the most common European languages of the 2.5 Million dyslexic school children. The project combines innovative analyses of how the reading problems relate to genes, environment, brain structure, and brain function. Nearly 4000 children will be assessed in this large coordinated effort, which is supplemented by several major national projects.

Building the largest biological database on dyslexia worldwide will put Europe at the forefront of dyslexia research in less than 3 years. The integration of new findings from the molecular, brain and behavioural studies will facilitate a thorough understanding of universal and language specific aspects in dyslexia. This provides a scientific basis for more effective targeted diagnosis and treatment.

Dyslexia is one of the very common learning disorders around the world with prevalence about at least 5% - 10% of the school age children. At least 22,750,000 EU citizens are affected and perhaps another million in those countries seeking to join. Recent estimates of the Dyslexia Institute in the UK estimate that poor literacy and basic skills, as the result of unrecognized dyslexia, costs the UK economy £ 1 billion per year, which is a staggering £2.75 million daily. This cost for 2003/2004 for an individual taxpayer equates to approximately £34 per annum. The societal impact of dyslexia is as follows: higher incidence of dyslexia within the prison and probation populations, higher incidence of school drop out, higher incidence of long term unemployment. Other consequences for dyslexia include are that dyslexia increases the risk for psychiatric disorders like emotional and affective disorder, and conduct disorders.

Although some individuals show considerable amelioration of symptomatology with development and treatment, the core symptoms persist into adult life and the disorders are associated with significant morbidity across Europe. The development of novel specific treatments or strategies to prevent or ameliorate reading and spelling ability requires a proper understanding of the underlying molecular and neurological mechanisms. These advances are likely to be of general interest to society. In part that is because there is evidence that susceptibility loci predispose to dyslexia and to dyslexia related traits such as phonological and orthographic processing. It will be necessary for a proper appreciation of the complexity of the intervening mechanisms to understand the different dyslexia related quantitative traits.

So far the etiology of dyslexia is poorly understood. Therefore, it is mandatory to tackle the problem from several directions.

In a multicentre, multidisciplinary project we will investigate the biological basis of dyslexia by collecting powerful samples of subjects consistently characterized across EC populations on three different levels: genetics, environment, and neuroscience. Our aim is to understand the etiology of the disorder by integrating the results of the three levels.

On the genetic level, we will use a systematic two-stage approach to map and clone dyslexia susceptibility genes in samples of 800 families and 1900 dyslexic cases and 1900 controls. The identified risk-conferring genes will also be used to understand gene-gene and gene-environment interactions, as well as gene-specific contributions to a variety of neurobiological correlates of dyslexia. Identifying susceptibility alleles will be a key for developing an understanding of the molecular and cellular nature of the brain dysfunction, discovering the factors influencing phenotypic expression and for developing rational preventative and treatment strategies to improve quality of life.

Environmental risk factors will be investigated in two samples, a longitudinal sample of 4000 twin pairs and a longitudinal sample of 100 at-risk and 100 non at-risk children. Specifically, we will test for the presence of gene-gene and gene-phenotype relationships (interactions, epistasis/co-actions). The environmental factors include selected preschool home environmental factors such as articulation, vocabulary, and parent child interaction, which are candidate environmental risks factors in dyslexia. We will use a prospective longitudinal sample to investigate the potential early predictors of dyslexia, including neurophysiological and home environment measures, taking account of the new susceptibility genes identified.

On the neuroscience level we will investigate the prerequisites of reading and spelling development and the central stages of becoming a fluent reader. The proposal combines structural and functional brain information at different levels in order to understand better the functioning and dysfunctioning of the brain, and in order to gain new insight into mental processes. It is necessary to highlight the brain correlates of speech perception, grapheme-phoneme associations and visual word recognition in order to identify genetically driven brain dysfunctions related to important reading acquisition milestones that may lead to dyslexia. The ERP studies focus on the main prerequisite necessary for starting reading acquisition, that is, efficient speech perception and phoneme representations. The fMRI studies complement this approach by directly focusing on the processes that built on these spoken language milestones to acquire fluent written language skills like reading.

 

 

The knowledge gained in this project will lead to the discovery of the underlying causes of dyslexia and of the development early diagnostic instruments as well as specific treatments. The exploitation of new treatments approaches will improve health, and quality of life in Europe. Additionally, this offers new possibilities for wealth creation as new knowledge is exploited by industries developing rehabilitation, therapy, and diagnostic tools and as the financial burden on our health care systems is diminished.

We will provide information that will enable society to understand this disease, increasing public and governmental awareness of the scale of the problem, the underlying cause, the ongoing research, and the hope for new therapy.